Sailonline.org - Online Sailing

Facebook

Login

Support Sailonline

If you haven't already - join the SAILONLINE YACHT CLUB!

Please also consider making a donation - all amounts are greatly appreciated!

Tweets by @sailonline

Board » Technical Support » distance to go

Posted by Olive Posts 4 Registered at 2012-12-24 20:22:03	2012-12-30 09:18:14 - Re: distance to go
	That's all indifferent since the nonsense numbers lead us all astray. Who cares if it all makes sense when we "get close." Why play along at all. Sheeeze...
Posted by RainbowChaser Posts 2656 Registered at 2009-06-14 09:44:50	2012-12-30 09:22:52 - Re: distance to go
	evilonod - I can sympathise with your frustration, but rest assured there is no-one getting any advantage here. It really is all about the shape of the globe and how SOL's calculations are made. Please don't give up on us!
Posted by hmm Posts 118 Registered at 2011-11-03 13:35:22	2012-12-31 10:06:10 - Re: distance to go
	I believe I have now found the root cause of this problem. I have described it in my blog: http://blog.sol.hmm.iki.fi/2012/12/scoring-problem-on-races-crossing-idl.html
Posted by outlaw Posts 33 Registered at 2012-06-01 13:37:55	2012-12-31 17:07:52 - Re: distance to go
	As for the DTF calculations, how about simply calculating GC bearings to the next couple waypoints, then using GC distance to the best WP based on bearings + rounding direction. I suspect this may lessen server load as well. (see pic) Attachments world.jpg (155.6 KB)
Posted by hmm Posts 118 Registered at 2011-11-03 13:35:22	2013-01-02 11:45:03 - Re: distance to go
	I have also tried to explain the DTF calculation in more detail in my blog, check the post here: http://blog.sol.hmm.iki.fi/2013/01/dtf-calculation-problems-near-polar-area.html As I say in the post, the DTF calculation is run every 15 seconds for each boat, so changes to that code have to be made very carefully not to cause the server too much load. However, that doesn't mean that there will not be improvements in the future. It just means that the changes have to take into account also other things than only always getting the best possible DTF for the boat.
Posted by Rod Posts 392 Registered at 2010-06-24 22:30:48	2013-01-02 14:26:49 - Re: distance to go
	Is it not possible for each player (sailor ?) to merely run the measuring caliper tool, in Great Circle mode, between the next turning mark and the current position of any boat (including his own) in which he has an interest? I just do not understand the cause of all this worry over such a trivial problem. Congratulation to Markku H. for solving the causes of the SERVER'S problem, but it is really not a problem to the SAILOR. If it breaks, it's not strong enough--if it doesn't, it's too heavy.
Posted by outlaw Posts 33 Registered at 2012-06-01 13:37:55	2013-01-02 18:32:12 - Re: distance to go
	> the DTF calculation is run every 15 seconds for each boat This is unneeded, do a proper distance calculation every 16 steps, and use increments (VMC * timestep) inbetween. That means only one in 16 boats gets a full calculation for a given timestep. The same could be done for roundings, maybe. --- Zuletzt bearbeitet von outlaw am 2013-01-02 18:33:23 ---
Posted by hmm Posts 118 Registered at 2011-11-03 13:35:22	2013-01-02 19:25:05 - Re: distance to go
	To do that the VMC (and the course which to calculate VMC for) should be calculated for each boat every 15 seconds so it's not clear if it's easier to it that way. The VMC, VMG etc numbers you see at the client are calculated at in your own computer and are thus "cheap" for the server but on the other hand are not available there directly. It's good to have different ideas how to improve the calculation but as Rod wrote earlier I don't see it as a major problem now.
Posted by Hasseballad Posts 17 Registered at 2008-11-15 11:51:32	2014-05-25 07:33:33 - Re: distance to go
	Recent experience at RTW2014-leg4. The "rounding line" ref. hmm for Cape Horn has a limit at 83S & 34W. Why not move that limit to say 65S & 64.2W or the exact W pos. on the "rounding line". Wouldn't that be a simple improvement for the boat position at the Horn specificly. Rgds Hans

Page: Previous 1 2

Please login to post a reply.

Races

Next Race: 00d 00h 00m

Current Races:

Kapiti Chetwodes Race 2024

For only the second time in SOL history, we have the pleasure of inviting you to the Kapiti Chetwodes Race, held in the Cook Strait region. Organised IRL by the Royal Port Nicholson Yacht Club from Wellington in New Zealand. The approximately 160nm long route, full of turning points, will take us from the bay at RPNYC around the islands of Somes, Kapiti and Chetwodes and back to the finish line at RPNYC. We have only a 26 ft Albin 79 yacht at our disposal. All this means that we will have a lot of fun, so fair winds!
Race #1864
INFO by brainaid.de
Albin 79 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking:
ARQ4 - ARCH - SUPSOL - SYC
Race starts: Nov 25th 17:00 Registration Open!

▶ Flash

GO TO RACE

Raja Muda Selangor 2024 - Penang to Langkawi

Welcome to the third and last online race of the Raja Muda Selangor International offshore series – a 70nm final trip further north again up the Malacca Strait from Penang to the exotic island of Langkawi, and again in Ker 40s.
Race #1871
INFO by brainaid.de
Ker 40 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: RMS - SYC
RACE CLOSE: Monday,
November 25 at 2300 UTC.
Race starts: Nov 21st 04:00 Registration Open!

▶ Flash

GO TO RACE

Raja Muda Selangor 2024 - Pangkor to Penang

Welcome to our second online offshore race in cooperation with Raja Muda Selangor International – an 80nm trip from Pangkor north to Penang up the Malacca Strait, again in Ker 40s.
Race #1870
INFO by brainaid.de
Ker 40 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: RMS - SYC
RACE CLOSE: Saturday,
November 23 at 2300 UTC.
Race starts: Nov 18th 04:00 Registration Open!

▶ Flash

GO TO RACE

Two Oceans Doublecross TIMED Race 2024

Our November Timed race takes us to Cape Town near where the Atlantic and Indian oceans meet. Our ride is a beautiful ketch, the Archer 78. Starting at Cape Town, we’ll round Robben Island, then head south to round Cape Point, up around Seal Island before heading north to round Dassen Island before returning to Cape Town. This is a TIMED race, so you may RE-REGISTER HERE to try again, after finishing a run. You will have 13 days and 11 hours to test your skill and decision making after the race opens.
Race #1872
INFO by brainaid.de
Archer 78 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking:
TRQ4 - TRCH - SUPSOL - SYC
RACE CLOSE: Saturday,
30 November at 23:00 UTC
Race starts: Nov 17th 12:00 Registration Open!

▶ Flash

GO TO RACE

Nassau to Bodo 2024

Prepare for the grand finale - the 6th and concluding leg of the RTW challenge, an odyssey from Nassau in the Caribbean to Bodø in Norway. Embracing a journey of 4000 nautical miles, this leg promises an exhilarating 18-day voyage. It also heralds the November installment of our prestigious Ocean Race Championship. Embark on a voyage of a lifetime, where prowess, tactics, and camaraderie unite in the pursuit of triumph. We eagerly await your presence at the starting line! May the winds be ever in your favor.
PRIZE: SMPF
Race# 1866
INFO from brainaid.de
Swan 65 PARTICULARS
WX updates:
0430 / 1030 / 1630 / 2230
Ranking: OCQ4 - OCCH - RTW - SUPSOL - SYC
Race starts: Nov 11th 11:00 Registration Closed

▶ Flash

GO TO RACE

Go to race archive

SYC Ranking

View full list

Series

Mobile Client

SYC members have the benefit of access to our mobile/lightweight web client!

The mobile client